Do they really wash their hands? Prevalence estimates for personal hygiene behaviour during the coronavirus crisis based on indirect questions
Abstract Background: During the so-called coronavirus crisis, billions of people have to change their behaviours to slow down the pandemic. Protective measures include self-isolation, social (physical) distancing and compliance with personal hygiene rules, particularly regular and thorough hand washing. To adjust public information campaigns to the level of people’s commitment and to evaluate the effectiveness of these campaigns, valid information about the degree to which people comply with protective measures is desirable.Methods: However, during a health crisis there is strong public pressure to comply with health and safety regulations so that people’s responding in direct questionings may be seriously compromised by social desirability. Here we use an indirect questioning technique to test whether the prevalence of hygiene practices may be lower when confidentiality of responding is guaranteed.Results: In the direct questioning group 94.5 % of the participants claimed to practice proper hand hygiene; in the indirect questioning group a significantly lower estimate of only 78.1 % was observed.Conclusions: These results indicate that estimates of the degree of commitment to measures designed to counter the spread of the disease may be significantly inflated by social desirability in direct questionings. Indirect questioning techniques with higher levels of confidentiality seem helpful in obtaining more realistic estimates of the degree to which people follow the recommended personal hygiene measures.